// Edition1: 局部变量。

#include <stdio.h>

double temchange();

int main()
{
    double fahr, cel;

    printf("Please input the Fahr:");
    scanf("%lf", &fahr);

    cel = temchange(fahr, cel);

    printf("\nCel = %4.2lf\n", cel);

    return 0;
}

double temchange(double f, double c)
{
    printf("\nUsing temchange()...\n");
    c = 5.0 * (f - 32) / 9.0;
    return c;
}